A POS (Point of Sales) terminal is used as a settlement terminal when selling a commodity. Generally, these POS terminals are connected with an AC power supply and used. However, in recent years, commodity sales in outdoors where there is no AC power supply device is increasing and therefore a POS terminal provided with a secondary battery is used more and more frequently.
The charge/discharge operation is repeated on the used secondary battery, however, the deterioration of battery may be expedited if an improper charging method is used. Therefore, a method of quick charging without causing the deterioration of the battery performance of the secondary battery is being considered.
In a case where the deterioration of the secondary battery is taken into consideration, and the battery is in a charge state in which the battery level is below that in a full charge state, if the POS terminal is taken out, for the commodity sales, to the outdoors in that state, as the use of the terminal is stated in a state different from the full charge state, the use time of the terminal decreases compared with the terminal in the full charge state.